When you get down to it, natural selection is merely about who is able to create the most successful offspring. The fact that the offspring have very similar tr

When you get down to it, natural selection is merely about who is able to create the most successful offspring. The fact that the offspring have very similar traits as their parents is the reason why these offspring are themselves likely to reproduce successfully. The question then is weaker jaw muscles somehow became more prevalent than stronger ones. As I explained in another comment, this might be because the trait was able to survive recessively until a good genetic environment was available.